1. Field of the Invention
This invention relates to a bowling aid. More particularly, this invention relates to a bowling aid for use on a bowler's hand for controlling the bowling ball.
2. Description of the Prior Art
Bowling is a popular sport at both the leisure and competitive levels. In order to bowl at an intermediate or advanced level, the bowler must be able to swing and release the bowling ball with adequate lift, turn, axis rotation and axis tilt to produce the desired movement and rotation of the bowling ball as the ball travels down the bowling lane prior to striking the pins. The lift, turn, rotation, and tilt all combine to result in a specific path and movement so that the ball strikes the pins at the optimum position to produce the maximum pin count.
Lift is related to the time between when the bowler's thumb disengages from the bowling ball and when the bowler's fingers disengage from the bowling ball. Lift generates the revolution of the bowling ball, with high revolutions being desired. Stronger lift is developed by moving the hand behind and under the bowling ball during the release. This requires considerable strength in the fingers and the rest of the hand, especially the ring finger, which is substantially responsible for the lift generated in a bowling ball during release.
The track of the bowling ball is that portion of its surface contacting the lane as it is moving towards the pins. For present lane surface conditions, the ideal track is called a "semi-roller." This track is on the index finger side of bowling ball when the thumb and middle fingers are inserted into the grip holes. The track is adjacent to the thumb hole and middle finger gripping hole. The typical track has a length of about 10-12 inches around the bowling ball. Tracks of less than 10 inches are known as "spinner" tracks. They are typically indicative of a weak release, usually derived from minimal lift, early hand turn, or a late exiting thumb. These release variables can act alone or in combination to produce the spinner track. Spinner tracks have low revolution and a difficult time gripping the lane surface, and thus have very little energy when they strike the pins. The track has two axis points. In bowling jargon, the axis point on the small finger side of the hand with the bowler's thumb and two middle fingers inserted into the three gripping holes is termed the positive axis. The opposite axis is termed the negative axis.
During release, the positive axis is rotated by a right handed bowler in a counter clockwise direction. Proper axis rotation will result in the positive axis point centered and facing the bowler just after release. This process of axis rotation is effected through the "turn" which occurs during the release of the ball. The middle finger inserted into the bowling ball is substantially responsible for the "turn" generated during release. Turn is the second key ingredient of a proper release, the first being lift.
Both lift and turn occur after the thumb has exited the bowling ball during delivery. Adequate revolutions and axis rotation are not obtained without the proper amount of lift and turn. Inadequate lift and/or turn will reduce the strike power of the bowling ball. The index finger is particularly important in the stabilization of the bowling ball during release and leads the hand in the turning motion. Thus, bowlers with long fingers and strong hands have more potential to lift and turn the bowling ball properly during the release.
As the bowling ball moves down the lane, the positive axis begins to rotate towards the strike pocket. This movement of the axis is called axis tilt. If the bowling ball has been properly turned during the release to establish optimum axis rotation, the energy of the release will be retained long enough to allow the axis tilt to occur as the ball begins to grip the last one-third of lane surface in front of the bowling pins. The axis tilt continues as the ball strikes the pins. Inadequate axis rotation will result in inadequate axis tilt, and thus premature energy release. This produces a weak-hitting bowling ball since the energy of the bowling ball was released prior to striking the pins. In bowling jargon this is called a "roll out."
Bowling balls conventionally have three holes formed therein for receiving the bowler's thumb and middle fingers with the palm of the hand resting on the surface of the ball, and the index and little finger extending along the surface of the bowling ball. The insertion of the fingers into the holes allows the bowler to grip the ball adequately and hold the ball during the back swing and release thereof. The inserted fingers assist in generating the lift, turn, axis rotation, and axis tilt, as described above, necessary for controlling the movement of the bowling ball. The palm, index finger and little finger also contribute to the lift, axis rotation and axis tilt.
A person of normal strength often has a difficult time maximizing the lift, turn, axis rotation, and axis tilt of the bowling ball during release given the relatively small surface area of the index finger, little finger, and palm in contact with the outer surface of the bowling ball. As a result, the bowler's ability to develop into an advanced bowler is limited.
Various devices have been developed in an attempt to address the inherent limitation of the bowler's ability to generate the necessary lift, turn, axis rotation, and axis tilt. Some devices have emphasized improving the control of the bowling ball by the bowler's fingers by providing a flexible rubber finger cot which is placed on the finger. This device still only has a surface area in contact with the bowling ball similar in size to the surface area of a natural finger.
Other devices have attempted to improve the bowler's delivery of the bowling ball by spacing certain portions of the bowler's hand and fingers off of the bowling ball. These devices can lift the index finger and pull it off the ball, thereby decreasing the user's control of the ball and lessening the effectiveness of the finger to which it is applied. Still other devices have attempted to improve the bowler's performance by restricting the movement of the bowler's wrists. Locked wrist devices can inhibit the user's ability to generate optimum lift and turn during the release. The locked wrist devices can either produce an excess amount of lift with inadequate turn, or inadequate lift with excessive, early hand turn. In addition, they do not allow free wrist motion through the release.
A flexible sheath for the index finger, with a tacky surface for engagement with the surface of a bowling ball, is disclosed in "Bowling," June/July, 1984, at page 39. A glove with sheaths for the bowler's index and little fingers and a flexible strap tying the sheaths together, and non-slip surface for engagement with a bowling ball is shown in U.S. Pat. Nos. 3,595,575 and 3,224,012. A finger sheath formed of a flexible, resilient material for frictionally engaging a bowling ball is shown in U.S. Pat. No. 3,091,455.
Flexible covers for a bowler's index and little fingers are shown in U.S. Pat. No. 3,248,112. The covers have ribbed surfaces for frictionally engaging the bowling ball. A wraparound sleeve and integral stiff tongue brace is shown in U.S. Pat. No. 4,194,736.